CHEMILUMINESCENCE DETERMINATION OF NITRATE WITH PHOTOCHEMICAL ACTIVATION IN A FLOW-INJECTION SYSTEM

A chemiluminescence flow injection system is described for the determi nation of nitrate, involving use of a laboratory-built flow-through ph otochemical reactor. Optimum analytical conditions were established. T he linear range for nitrate is 7 x 10(-8)-1 x 10(-4)M. The sampling fr equency is 60 samples per hour. The relative standard deviation for 1 x 10(-7), 1 x 10(-6) and 1 x 10(-5)M nitrate is 0.97, 0.84 and 0.76%, respectively. The method has been applied to the determination of nitr ate in natural water samples, and recoveries of 96-103% have been atta ined.